With the July 31 trade deadline closing in, the MLB trade market is only beginning to heat up.

The All-Star break presents general managers with an opportunity to explore trade options for the second half of the season. As the Home Run Derby and All-Star game are going on, GMs are often actively discussing trade scenarios and keying in on moves that will improve their respective teams down the stretch.

The trade market has been relatively quiet to this point, but several big names have been bandied about as potential trade-deadline movers—among them, Giancarlo Stanton, Matt Garza and Kendrys Morales.

Kendrys Morales, Seattle Mariners

With the Seattle Mariners currently sitting at 43-52 and 13 games back of the Oakland Athletics in the American League West, it may be time for general manager Jack Zduriencik to consider selling before the trade deadline.

The Mariners have some quality pieces in place, but making a run at the division title probably isn’t in the cards. As such, first baseman Kendrys Morales could be on the move.

As noted by Nick Cafardo of The Boston Globe, Morales has been drawing some interest from around the league as teams search for a switch-hitting power bat to augment the middle of their respective lineups.

Hitting .280 with 14 home runs and 54 RBI this season, Morales could be that player. And according to ESPN’s Buster Olney, the Pittsburgh Pirates are a possible landing spot:

The Pirates aren’t used to being in the buyer role at this point in the season, but at 56-37 and just a game back of the St. Louis Cardinals, they can’t afford to stand pat and hope things pan out in the second half.

Pittsburgh is closing in on an historic season after failing to break the .500 mark in any season since 1992. If the Pirates hope to end that drought—and possibly make a World Series run—they’ll need to continue exploring their options. Morales wouldn’t be a bad choice.

Giancarlo Stanton, Miami Marlins

As far as rumors go, this one is likely go undeveloped as the trade deadline approaches.

According to Jon Heyman of CBS Sports, the Texas Rangers have been asking about Marlins outfielder Giancarlo Stanton, no doubt searching for another big bat to make a push in the AL West:

While Miami has been in selling mode since last season, it seems unlikely the Marlins would trade their best player—a player making $537,000 this year—to bring back a couple prospects and prolong the rebuilding process.

Danny Knobler of CBS Sports mirrors that sentiment, noting that Miami appears to be moving even further from trading Stanton:

The Marlins continue to indicate that Stanton isn't available now. If anything has changed, it's that they could be moving farther away from trading their biggest remaining star, rather than closer.

In other words, don't count on them moving him this winter, either.

Miami could certainly expect a sizable return for the slugger, though.

Last season, the 23-year-old batted .290 with 37 home runs and 86 RBI, that on the heels of a .262/34/87 campaign in 2011. While he’s come back to earth in 2013 (.250 with 10 home runs and 27 RBI), he’s still worthy of a few top prospects in a trade scenario.

Still, the Marlins dealt most of their top talent last season in order to save money, and Stanton is costing them very little right now. It’s hard to envision a scenario in which the Rangers—or any team—will be willing to give up enough to acquire him.

Matt Garza, Chicago Cubs

Chicago Cubs starter Matt Garza has been pitching extremely well this season, and according to David Kaplan of CSN Chicago, that may be enough for the Cubs to get a massive return for the right-hander:

Garza carries a 6-1 record and a 3.17 ERA into the All-Star break—strong-enough marks to justify sizable interest from around the league.

Per Olney (subscription required), at least five teams are actively interested in the starter:

The Chicago Cubs are making progress in their discussions about right-hander Matt Garza, and are actively talking with Texas, Boston, Toronto, Cleveland, the Dodgers and maybe Baltimore and a couple of more teams in the NL West. Right now, Garza is the belle of the ball in the trade market.

Each of those teams is in contention and could use another solid rotation arm going forward. Every team on the list has at least one substantial front-end starter, but Garza would be a solid No. 2 or No. 3 option for any team in that group.